International 7400 front turn signal bulbs utilize 3157NA size while rear turn signal bulbs use 3157 size. The replacement chart contains bulb specifications covering 2008 through 2017 production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International 7400 uses the 3157NA bulb for the front turn signal across all listed model years, 2008-2017.
The rear turn signal on the International 7400 uses the 3157 bulb across the same 2008-2017 span.
Both the 3157NA and 3157 are dual-filament T25 wedge bulbs rated at 12V with a 27W/7W power split, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary function such as running light operation.
The 3157NA and 3157 share the same ANSI designation base, T25 wedge form factor, voltage rating, and wattage, making them physically and electrically equivalent in those respects.
The distinguishing characteristic of the 3157NA is its natural amber glass envelope, which filters the light output to produce an amber color without relying on an amber lens housing.
The 3157, by contrast, uses a clear glass envelope, so the amber color of the turn signal output depends on the color of the lens housing rather than the bulb itself.
Because the 3157NA produces amber light through the glass itself, substituting a clear 3157 in the front turn signal position could result in non-amber light output if the lens housing is also clear, which may not meet regulatory requirements for turn signal color.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized base dimensions and electrical characteristics within that regulatory framework.